The Second North Korean Nuclear Test

North Korea announced today that they have conducted test of a test of a nuclear weapon. Coming on the heals of their failed satellite launch attempt April 5th, the DPRK made sure to point out in their announcement that this one had a higher yield than their last test. Estimates first varied on the yield of that test but Western analysts generally settled on a value of about ½ kiloton. The North’s announcement today seems to concede that the first test had problems:

The current nuclear test was safely conducted on a new higher level in terms of its explosive power and technology of its control and the results of the test helped satisfactorily settle the scientific and technological problems arising in further increasing the power of nuclear weapons and steadily developing nuclear technology.

No word yet of independent assessments of the test’s yield or even that it took place. Watch this space for further information and analysis as it becomes available.

Update (7:50am): 20 kilotons certainly seems to say that they went with the “safest” weapon design possible to ensure that they got a good bang.

Update (11 am): 2009 test appears to be in roughly the same location as the 2006 test. (Remember there are errors associated with both these positions; the largest being associated with first location for the latest test.)

click on the image for a larger version
(For some reason, GoogleEarth seems to have presented the titles of the two sites reversed: the new location is actually to the West of the 2006 location. However, the kmz file below IS correct.)

Hang on, Itar-Tass may have it at around 20 KTons, but RIA Novostii and Interfax both have it at 10-20. Seems there’s some wires crossed/conservative estimating somewhere:

“The special control service of the Defense Ministry of the Russian Federation registered an underground nuclear explosion equivalent to 10-20 kilotons in the territory of the DPRK at 04:54:41 a.m. (Moscow time) (0054 GMT) on May 25,”

Okay, let’s have a sweep-stake, everyone take a half-kiloton increment. Grab them whilst they’re (radioactively) hot! I’m taking 6.5 KTons – so far Russia has over-estimated pretty much everything that North Korea does.

Jan

May 25, 2009 at 8:22 am

Apparently Yonhap News is the source for the information about the missile launch (link):

A source, who declined to be named, said North Korea coupled the detonation with a test of a short-range missile from a coastal base where the communist regime conducted its April 5 rocket launch.

They also quote Russian media about the yield:

Russia said the “nuclear explosion” appears to have had a force of up to 20 kilotons, according to its state media.

Hmm, cannot find anything on the English itar-tass website about that.

Isn’t this some sort of recognizable pattern: first a failed Taepodong-test, then a (failed?) nuclear test – this is 2006 all over again!

But the North Koreans apparently learn from their failed tests (something that i personally would associate with a real development program), since both 2009 tests (missile and bomb) obviously worked better than their 2006-counterparts…

Considering the 20kt-figure: i’d suggest that this one is possibly some sort of snapshot by the Russians – a yield of “up to 20kt” would be a typical figure for a unboosted (fission-only) implosion-type nuclear device…and at the same time, lower actual yields like 1kt or 5kt (indicating perhaps a “fizzle”) are not excluded. What do you all make of the purported Richter-value of 4.5 (measured somewhere in South Korea)? I’m looking forward to the findings of a more thorough analysis.

Tim

May 25, 2009 at 1:02 pm

Geoff,

The best place to look for confirmation of these things is the USGS website which is updated in real time:

What about the missile launch? According to REUTERS (http://www.reuters.com/article/idUSTRE54O0EU20090525) , the DPRK launched a surface to air missile with a range of 130km. Do you think it actually was a surface-to-surface missile (KN-02 type)? Why would they test a SAM after the nuclear test?